Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 41,863	$ 67,252
Restricted cash	0	65
Trade accounts receivable, net of allowances of $414 in 2021 and $6,824 in 2020	79,118	64,078
Inventories	72,286	76,658
Assets of discontinued operations	0	710,006
Prepaid expenses and other current assets	16,121	13,487
Total current assets	209,388	931,546
Property, plant, and equipment:
Land and building	26,405	26,506
Machinery and equipment	343,181	365,296
Automobiles and trucks	16,335	18,446
Chemical plants	61,374	62,714
Construction in progress	4,575	1,526
Total property, plant, and equipment	451,870	474,488
Less accumulated depreciation	(364,522)	(377,632)
Net property, plant, and equipment	87,348	96,856
Other assets:
Patents, trademarks and other intangible assets, net of accumulated amortization of $69,186 in 2021 and $66,078 in 2020	38,071	41,487
Deferred tax assets, net	44	52
Operating lease right-of-use assets	38,795	43,448
Investments	22,412	2,675
Other assets	15,178	16,775
Total other assets	114,500	104,437
Total assets	411,236	1,132,839
Current liabilities:
Trade accounts payable	41,268	22,573
Unearned income	1,432	2,675
Accrued liabilities and other	48,552	38,791
Liabilities of discontinued operations	1,327	734,039
Total current liabilities	92,579	798,078
Long-term debt, net	164,228	199,894
Deferred income taxes	1,817	1,942
Asset retirement obligations	12,840	12,484
Warrants liability	56	198
Operating lease liabilities	33,145	37,569
Other liabilities	6,493	11,612
Total long-term liabilities	218,579	263,699
Commitments and contingencies
Equity:
Common stock, par value 0.01 per share; 250,000,000 shares authorized at September 30, 2021 and December 31, 2020; 130,075,838 shares issued at September 30, 2021 and 128,930,047 shares issued at December 31, 2020	1,301	1,289
Additional paid-in capital	474,544	472,134
Treasury stock, at cost; 3,135,434 shares held at September 30, 2021, and 2,953,976 shares held at December 31, 2020	(19,945)	(19,484)
Accumulated other comprehensive loss	(45,518)	(49,914)
Retained deficit	(309,191)	(413,665)
Total TETRA stockholders’ equity	101,191	(9,640)
Noncontrolling interests	(1,113)	80,702
Total equity	100,078	71,062
Total liabilities and equity	$ 411,236	$ 1,132,839